DENVER  In an emotional meeting leading up to the Democratic roll call of the states, Hillary Rodham Clinton released her convention delegates Wednesday to vote for certain presidential nominee Barack Obama.

Many in the crowded ballroom yelled back, "No!"

"I am not telling you what to do," Clinton responded. "You've come here from so many different places having made this journey and feeling in your heart what is right for you to do."

Her speech, just a couple of hours before the nomination vote was scheduled, was frequently interrupted by shouts from the crowd, including a brief chant of "Roll call! Roll call!" signifying the desire of many of her delegates to have a chance to vote for her.

"You are to be given the respect and recognition you have earned as delegates," Clinton said. She insisted that however the delegates voted, "as Democrats and as Americans we will leave Denver united."

A roll call vote was scheduled for later in the afternoon after brief nominating speeches for both Clinton and Obama. The former rivals negotiated a plan that would cut off the split roll call after a few states -- perhaps by Clinton herself -- in favor of acclamation for Obama. She planned to sit with the New York delegation during the vote.

Delegates said they were frustrated that they did not have specific instructions on how the process would work or which states would participate, even as they received their ballots Wednesday morning. With Clinton's encouragement during the meeting and in a speech to the convention Tuesday night, a swell of Clinton delegates said they would support Obama.

"She's a supreme lady," said California delegate Marie McClintock as she left the meeting with Clinton. "I voted for Hillary this morning because I gave my word and I keep my word."

Massachusetts delegate Nancy Saboori was visibly upset at the end of Clinton's speech.

"She doesn't have the right to release us," Saboori argued. "We're not little kids to be told what to do in a half-hour."

Kathleen Krehbiel, Clinton's Iowa vote-counter, said she made up her mind to switch and believed most Clinton loyalists also were coming around.

"I did not want to see a floor fight," she said. "I don't see any further reason to continue to carry out a pretense that she's a candidate. She's not."

Not all Clinton supporters were on board. Sonja Jaquez Lewis, a Clinton delegate from Colorado, said she and others may walk out if Clinton is denied a roll call.

"If we don't have an official roll call vote, state-by-state, it is going to reopen a wound," Lewis said.

New Jersey Gov. Jon Corzine said Democrats from his state, which Clinton won, voted in private to unanimously support Obama.

"I think it is reflective of the unity that I sense that is building across the party," Corzine said. "That doesn't mean there won't be outliers that are still heartbroken their favorite candidate didn't make it."

Pennsylvania Gov. Ed Rendell, a Clinton supporter, said in an AP interview that he will vote for Obama "wistfully but enthusiastically." But Rendell estimated somewhere around 10 or 12 Clinton delegates from his state weren't "going to be able to bring themselves to vote for anybody other than Senator Clinton."

He insisted that's not a slight of Obama, rather a reflection of their hard work for Clinton and their deep admiration for her and her bid to become the first woman president.

"Even though Hillary tells us not to spend any time thinking about what might have been," he said, pausing as tears welled in his eyes, "I'm sure all of us were thinking about what might have been last night."

Missouri Sen. Claire McCaskill, an Obama supporter, said Clinton's challenge in getting her delegates to come on board with Obama "may be the biggest test of her leadership."

"If she's not a strong enough leader to get her followers to do what's right for America, then that would surprise me," McCaskill told the AP. "I think they are going to follow her lead, and her lead was very crystal clear last night."

Wyoming state Sen. Mike Massie, D-Laramie, said his delegation gave 12 votes to Obama and six to Clinton after state party officials rejected a request from Clinton delegates to delay the vote until after a meeting later in the day with Clinton. Massie said the delegation is still puzzled by orders to vote before Clinton could meet with her delegates and release them.

To report corrections and clarifications, contact Reader Editor Brent Jones. For publication consideration in the newspaper, send comments to letters@usatoday.com. Include name, phone number, city and state for verification.

Guidelines: You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. Read more.